diff options
Diffstat (limited to 'drivers/usb/core/usb.c')
| -rw-r--r-- | drivers/usb/core/usb.c | 1159 |
1 files changed, 1159 insertions, 0 deletions
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c new file mode 100644 index 000000000..3500e3c94 --- /dev/null +++ b/drivers/usb/core/usb.c @@ -0,0 +1,1159 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * drivers/usb/core/usb.c + * + * (C) Copyright Linus Torvalds 1999 + * (C) Copyright Johannes Erdfelt 1999-2001 + * (C) Copyright Andreas Gal 1999 + * (C) Copyright Gregory P. Smith 1999 + * (C) Copyright Deti Fliegl 1999 (new USB architecture) + * (C) Copyright Randy Dunlap 2000 + * (C) Copyright David Brownell 2000-2004 + * (C) Copyright Yggdrasil Computing, Inc. 2000 + * (usb_device_id matching changes by Adam J. Richter) + * (C) Copyright Greg Kroah-Hartman 2002-2003 + * + * Released under the GPLv2 only. + * + * NOTE! This is not actually a driver at all, rather this is + * just a collection of helper routines that implement the + * generic USB things that the real drivers can use.. + * + * Think of this as a "USB library" rather than anything else, + * with no callbacks. Callbacks are evil. + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/string.h> +#include <linux/bitops.h> +#include <linux/slab.h> +#include <linux/kmod.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/errno.h> +#include <linux/usb.h> +#include <linux/usb/hcd.h> +#include <linux/mutex.h> +#include <linux/workqueue.h> +#include <linux/debugfs.h> +#include <linux/usb/of.h> + +#include <asm/io.h> +#include <linux/scatterlist.h> +#include <linux/mm.h> +#include <linux/dma-mapping.h> + +#include "hub.h" + +const char *usbcore_name = "usbcore"; + +static bool nousb; /* Disable USB when built into kernel image */ + +module_param(nousb, bool, 0444); + +/* + * for external read access to <nousb> + */ +int usb_disabled(void) +{ + return nousb; +} +EXPORT_SYMBOL_GPL(usb_disabled); + +#ifdef CONFIG_PM +/* Default delay value, in seconds */ +static int usb_autosuspend_delay = CONFIG_USB_AUTOSUSPEND_DELAY; +module_param_named(autosuspend, usb_autosuspend_delay, int, 0644); +MODULE_PARM_DESC(autosuspend, "default autosuspend delay"); + +#else +#define usb_autosuspend_delay 0 +#endif + +static bool match_endpoint(struct usb_endpoint_descriptor *epd, + struct usb_endpoint_descriptor **bulk_in, + struct usb_endpoint_descriptor **bulk_out, + struct usb_endpoint_descriptor **int_in, + struct usb_endpoint_descriptor **int_out) +{ + switch (usb_endpoint_type(epd)) { + case USB_ENDPOINT_XFER_BULK: + if (usb_endpoint_dir_in(epd)) { + if (bulk_in && !*bulk_in) { + *bulk_in = epd; + break; + } + } else { + if (bulk_out && !*bulk_out) { + *bulk_out = epd; + break; + } + } + + return false; + case USB_ENDPOINT_XFER_INT: + if (usb_endpoint_dir_in(epd)) { + if (int_in && !*int_in) { + *int_in = epd; + break; + } + } else { + if (int_out && !*int_out) { + *int_out = epd; + break; + } + } + + return false; + default: + return false; + } + + return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) && + (!int_in || *int_in) && (!int_out || *int_out); +} + +/** + * usb_find_common_endpoints() -- look up common endpoint descriptors + * @alt: alternate setting to search + * @bulk_in: pointer to descriptor pointer, or NULL + * @bulk_out: pointer to descriptor pointer, or NULL + * @int_in: pointer to descriptor pointer, or NULL + * @int_out: pointer to descriptor pointer, or NULL + * + * Search the alternate setting's endpoint descriptors for the first bulk-in, + * bulk-out, interrupt-in and interrupt-out endpoints and return them in the + * provided pointers (unless they are NULL). + * + * If a requested endpoint is not found, the corresponding pointer is set to + * NULL. + * + * Return: Zero if all requested descriptors were found, or -ENXIO otherwise. + */ +int usb_find_common_endpoints(struct usb_host_interface *alt, + struct usb_endpoint_descriptor **bulk_in, + struct usb_endpoint_descriptor **bulk_out, + struct usb_endpoint_descriptor **int_in, + struct usb_endpoint_descriptor **int_out) +{ + struct usb_endpoint_descriptor *epd; + int i; + + if (bulk_in) + *bulk_in = NULL; + if (bulk_out) + *bulk_out = NULL; + if (int_in) + *int_in = NULL; + if (int_out) + *int_out = NULL; + + for (i = 0; i < alt->desc.bNumEndpoints; ++i) { + epd = &alt->endpoint[i].desc; + + if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out)) + return 0; + } + + return -ENXIO; +} +EXPORT_SYMBOL_GPL(usb_find_common_endpoints); + +/** + * usb_find_common_endpoints_reverse() -- look up common endpoint descriptors + * @alt: alternate setting to search + * @bulk_in: pointer to descriptor pointer, or NULL + * @bulk_out: pointer to descriptor pointer, or NULL + * @int_in: pointer to descriptor pointer, or NULL + * @int_out: pointer to descriptor pointer, or NULL + * + * Search the alternate setting's endpoint descriptors for the last bulk-in, + * bulk-out, interrupt-in and interrupt-out endpoints and return them in the + * provided pointers (unless they are NULL). + * + * If a requested endpoint is not found, the corresponding pointer is set to + * NULL. + * + * Return: Zero if all requested descriptors were found, or -ENXIO otherwise. + */ +int usb_find_common_endpoints_reverse(struct usb_host_interface *alt, + struct usb_endpoint_descriptor **bulk_in, + struct usb_endpoint_descriptor **bulk_out, + struct usb_endpoint_descriptor **int_in, + struct usb_endpoint_descriptor **int_out) +{ + struct usb_endpoint_descriptor *epd; + int i; + + if (bulk_in) + *bulk_in = NULL; + if (bulk_out) + *bulk_out = NULL; + if (int_in) + *int_in = NULL; + if (int_out) + *int_out = NULL; + + for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) { + epd = &alt->endpoint[i].desc; + + if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out)) + return 0; + } + + return -ENXIO; +} +EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse); + +/** + * usb_find_endpoint() - Given an endpoint address, search for the endpoint's + * usb_host_endpoint structure in an interface's current altsetting. + * @intf: the interface whose current altsetting should be searched + * @ep_addr: the endpoint address (number and direction) to find + * + * Search the altsetting's list of endpoints for one with the specified address. + * + * Return: Pointer to the usb_host_endpoint if found, %NULL otherwise. + */ +static const struct usb_host_endpoint *usb_find_endpoint( + const struct usb_interface *intf, unsigned int ep_addr) +{ + int n; + const struct usb_host_endpoint *ep; + + n = intf->cur_altsetting->desc.bNumEndpoints; + ep = intf->cur_altsetting->endpoint; + for (; n > 0; (--n, ++ep)) { + if (ep->desc.bEndpointAddress == ep_addr) + return ep; + } + return NULL; +} + +/** + * usb_check_bulk_endpoints - Check whether an interface's current altsetting + * contains a set of bulk endpoints with the given addresses. + * @intf: the interface whose current altsetting should be searched + * @ep_addrs: 0-terminated array of the endpoint addresses (number and + * direction) to look for + * + * Search for endpoints with the specified addresses and check their types. + * + * Return: %true if all the endpoints are found and are bulk, %false otherwise. + */ +bool usb_check_bulk_endpoints( + const struct usb_interface *intf, const u8 *ep_addrs) +{ + const struct usb_host_endpoint *ep; + + for (; *ep_addrs; ++ep_addrs) { + ep = usb_find_endpoint(intf, *ep_addrs); + if (!ep || !usb_endpoint_xfer_bulk(&ep->desc)) + return false; + } + return true; +} +EXPORT_SYMBOL_GPL(usb_check_bulk_endpoints); + +/** + * usb_check_int_endpoints - Check whether an interface's current altsetting + * contains a set of interrupt endpoints with the given addresses. + * @intf: the interface whose current altsetting should be searched + * @ep_addrs: 0-terminated array of the endpoint addresses (number and + * direction) to look for + * + * Search for endpoints with the specified addresses and check their types. + * + * Return: %true if all the endpoints are found and are interrupt, + * %false otherwise. + */ +bool usb_check_int_endpoints( + const struct usb_interface *intf, const u8 *ep_addrs) +{ + const struct usb_host_endpoint *ep; + + for (; *ep_addrs; ++ep_addrs) { + ep = usb_find_endpoint(intf, *ep_addrs); + if (!ep || !usb_endpoint_xfer_int(&ep->desc)) + return false; + } + return true; +} +EXPORT_SYMBOL_GPL(usb_check_int_endpoints); + +/** + * usb_find_alt_setting() - Given a configuration, find the alternate setting + * for the given interface. + * @config: the configuration to search (not necessarily the current config). + * @iface_num: interface number to search in + * @alt_num: alternate interface setting number to search for. + * + * Search the configuration's interface cache for the given alt setting. + * + * Return: The alternate setting, if found. %NULL otherwise. + */ +struct usb_host_interface *usb_find_alt_setting( + struct usb_host_config *config, + unsigned int iface_num, + unsigned int alt_num) +{ + struct usb_interface_cache *intf_cache = NULL; + int i; + + if (!config) + return NULL; + for (i = 0; i < config->desc.bNumInterfaces; i++) { + if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber + == iface_num) { + intf_cache = config->intf_cache[i]; + break; + } + } + if (!intf_cache) + return NULL; + for (i = 0; i < intf_cache->num_altsetting; i++) + if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num) + return &intf_cache->altsetting[i]; + + printk(KERN_DEBUG "Did not find alt setting %u for intf %u, " + "config %u\n", alt_num, iface_num, + config->desc.bConfigurationValue); + return NULL; +} +EXPORT_SYMBOL_GPL(usb_find_alt_setting); + +/** + * usb_ifnum_to_if - get the interface object with a given interface number + * @dev: the device whose current configuration is considered + * @ifnum: the desired interface + * + * This walks the device descriptor for the currently active configuration + * to find the interface object with the particular interface number. + * + * Note that configuration descriptors are not required to assign interface + * numbers sequentially, so that it would be incorrect to assume that + * the first interface in that descriptor corresponds to interface zero. + * This routine helps device drivers avoid such mistakes. + * However, you should make sure that you do the right thing with any + * alternate settings available for this interfaces. + * + * Don't call this function unless you are bound to one of the interfaces + * on this device or you have locked the device! + * + * Return: A pointer to the interface that has @ifnum as interface number, + * if found. %NULL otherwise. + */ +struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev, + unsigned ifnum) +{ + struct usb_host_config *config = dev->actconfig; + int i; + + if (!config) + return NULL; + for (i = 0; i < config->desc.bNumInterfaces; i++) + if (config->interface[i]->altsetting[0] + .desc.bInterfaceNumber == ifnum) + return config->interface[i]; + + return NULL; +} +EXPORT_SYMBOL_GPL(usb_ifnum_to_if); + +/** + * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number. + * @intf: the interface containing the altsetting in question + * @altnum: the desired alternate setting number + * + * This searches the altsetting array of the specified interface for + * an entry with the correct bAlternateSetting value. + * + * Note that altsettings need not be stored sequentially by number, so + * it would be incorrect to assume that the first altsetting entry in + * the array corresponds to altsetting zero. This routine helps device + * drivers avoid such mistakes. + * + * Don't call this function unless you are bound to the intf interface + * or you have locked the device! + * + * Return: A pointer to the entry of the altsetting array of @intf that + * has @altnum as the alternate setting number. %NULL if not found. + */ +struct usb_host_interface *usb_altnum_to_altsetting( + const struct usb_interface *intf, + unsigned int altnum) +{ + int i; + + for (i = 0; i < intf->num_altsetting; i++) { + if (intf->altsetting[i].desc.bAlternateSetting == altnum) + return &intf->altsetting[i]; + } + return NULL; +} +EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting); + +struct find_interface_arg { + int minor; + struct device_driver *drv; +}; + +static int __find_interface(struct device *dev, const void *data) +{ + const struct find_interface_arg *arg = data; + struct usb_interface *intf; + + if (!is_usb_interface(dev)) + return 0; + + if (dev->driver != arg->drv) + return 0; + intf = to_usb_interface(dev); + return intf->minor == arg->minor; +} + +/** + * usb_find_interface - find usb_interface pointer for driver and device + * @drv: the driver whose current configuration is considered + * @minor: the minor number of the desired device + * + * This walks the bus device list and returns a pointer to the interface + * with the matching minor and driver. Note, this only works for devices + * that share the USB major number. + * + * Return: A pointer to the interface with the matching major and @minor. + */ +struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) +{ + struct find_interface_arg argb; + struct device *dev; + + argb.minor = minor; + argb.drv = &drv->drvwrap.driver; + + dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface); + + /* Drop reference count from bus_find_device */ + put_device(dev); + + return dev ? to_usb_interface(dev) : NULL; +} +EXPORT_SYMBOL_GPL(usb_find_interface); + +struct each_dev_arg { + void *data; + int (*fn)(struct usb_device *, void *); +}; + +static int __each_dev(struct device *dev, void *data) +{ + struct each_dev_arg *arg = (struct each_dev_arg *)data; + + /* There are struct usb_interface on the same bus, filter them out */ + if (!is_usb_device(dev)) + return 0; + + return arg->fn(to_usb_device(dev), arg->data); +} + +/** + * usb_for_each_dev - iterate over all USB devices in the system + * @data: data pointer that will be handed to the callback function + * @fn: callback function to be called for each USB device + * + * Iterate over all USB devices and call @fn for each, passing it @data. If it + * returns anything other than 0, we break the iteration prematurely and return + * that value. + */ +int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *)) +{ + struct each_dev_arg arg = {data, fn}; + + return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev); +} +EXPORT_SYMBOL_GPL(usb_for_each_dev); + +/** + * usb_release_dev - free a usb device structure when all users of it are finished. + * @dev: device that's been disconnected + * + * Will be called only by the device core when all users of this usb device are + * done. + */ +static void usb_release_dev(struct device *dev) +{ + struct usb_device *udev; + struct usb_hcd *hcd; + + udev = to_usb_device(dev); + hcd = bus_to_hcd(udev->bus); + + usb_destroy_configuration(udev); + usb_release_bos_descriptor(udev); + of_node_put(dev->of_node); + usb_put_hcd(hcd); + kfree(udev->product); + kfree(udev->manufacturer); + kfree(udev->serial); + kfree(udev); +} + +static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct usb_device *usb_dev; + + usb_dev = to_usb_device(dev); + + if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum)) + return -ENOMEM; + + if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum)) + return -ENOMEM; + + return 0; +} + +#ifdef CONFIG_PM + +/* USB device Power-Management thunks. + * There's no need to distinguish here between quiescing a USB device + * and powering it down; the generic_suspend() routine takes care of + * it by skipping the usb_port_suspend() call for a quiesce. And for + * USB interfaces there's no difference at all. + */ + +static int usb_dev_prepare(struct device *dev) +{ + return 0; /* Implement eventually? */ +} + +static void usb_dev_complete(struct device *dev) +{ + /* Currently used only for rebinding interfaces */ + usb_resume_complete(dev); +} + +static int usb_dev_suspend(struct device *dev) +{ + return usb_suspend(dev, PMSG_SUSPEND); +} + +static int usb_dev_resume(struct device *dev) +{ + return usb_resume(dev, PMSG_RESUME); +} + +static int usb_dev_freeze(struct device *dev) +{ + return usb_suspend(dev, PMSG_FREEZE); +} + +static int usb_dev_thaw(struct device *dev) +{ + return usb_resume(dev, PMSG_THAW); +} + +static int usb_dev_poweroff(struct device *dev) +{ + return usb_suspend(dev, PMSG_HIBERNATE); +} + +static int usb_dev_restore(struct device *dev) +{ + return usb_resume(dev, PMSG_RESTORE); +} + +static const struct dev_pm_ops usb_device_pm_ops = { + .prepare = usb_dev_prepare, + .complete = usb_dev_complete, + .suspend = usb_dev_suspend, + .resume = usb_dev_resume, + .freeze = usb_dev_freeze, + .thaw = usb_dev_thaw, + .poweroff = usb_dev_poweroff, + .restore = usb_dev_restore, + .runtime_suspend = usb_runtime_suspend, + .runtime_resume = usb_runtime_resume, + .runtime_idle = usb_runtime_idle, +}; + +#endif /* CONFIG_PM */ + + +static char *usb_devnode(struct device *dev, + umode_t *mode, kuid_t *uid, kgid_t *gid) +{ + struct usb_device *usb_dev; + + usb_dev = to_usb_device(dev); + return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d", + usb_dev->bus->busnum, usb_dev->devnum); +} + +struct device_type usb_device_type = { + .name = "usb_device", + .release = usb_release_dev, + .uevent = usb_dev_uevent, + .devnode = usb_devnode, +#ifdef CONFIG_PM + .pm = &usb_device_pm_ops, +#endif +}; + + +/* Returns 1 if @usb_bus is WUSB, 0 otherwise */ +static unsigned usb_bus_is_wusb(struct usb_bus *bus) +{ + struct usb_hcd *hcd = bus_to_hcd(bus); + return hcd->wireless; +} + +static bool usb_dev_authorized(struct usb_device *dev, struct usb_hcd *hcd) +{ + struct usb_hub *hub; + + if (!dev->parent) + return true; /* Root hub always ok [and always wired] */ + + switch (hcd->dev_policy) { + case USB_DEVICE_AUTHORIZE_NONE: + default: + return false; + + case USB_DEVICE_AUTHORIZE_ALL: + return true; + + case USB_DEVICE_AUTHORIZE_INTERNAL: + hub = usb_hub_to_struct_hub(dev->parent); + return hub->ports[dev->portnum - 1]->connect_type == + USB_PORT_CONNECT_TYPE_HARD_WIRED; + } +} + +/** + * usb_alloc_dev - usb device constructor (usbcore-internal) + * @parent: hub to which device is connected; null to allocate a root hub + * @bus: bus used to access the device + * @port1: one-based index of port; ignored for root hubs + * + * Context: task context, might sleep. + * + * Only hub drivers (including virtual root hub drivers for host + * controllers) should ever call this. + * + * This call may not be used in a non-sleeping context. + * + * Return: On success, a pointer to the allocated usb device. %NULL on + * failure. + */ +struct usb_device *usb_alloc_dev(struct usb_device *parent, + struct usb_bus *bus, unsigned port1) +{ + struct usb_device *dev; + struct usb_hcd *usb_hcd = bus_to_hcd(bus); + unsigned root_hub = 0; + unsigned raw_port = port1; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return NULL; + + if (!usb_get_hcd(usb_hcd)) { + kfree(dev); + return NULL; + } + /* Root hubs aren't true devices, so don't allocate HCD resources */ + if (usb_hcd->driver->alloc_dev && parent && + !usb_hcd->driver->alloc_dev(usb_hcd, dev)) { + usb_put_hcd(bus_to_hcd(bus)); + kfree(dev); + return NULL; + } + + device_initialize(&dev->dev); + dev->dev.bus = &usb_bus_type; + dev->dev.type = &usb_device_type; + dev->dev.groups = usb_device_groups; + set_dev_node(&dev->dev, dev_to_node(bus->sysdev)); + dev->state = USB_STATE_ATTACHED; + dev->lpm_disable_count = 1; + atomic_set(&dev->urbnum, 0); + + INIT_LIST_HEAD(&dev->ep0.urb_list); + dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; + dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; + /* ep0 maxpacket comes later, from device descriptor */ + usb_enable_endpoint(dev, &dev->ep0, false); + dev->can_submit = 1; + + /* Save readable and stable topology id, distinguishing devices + * by location for diagnostics, tools, driver model, etc. The + * string is a path along hub ports, from the root. Each device's + * dev->devpath will be stable until USB is re-cabled, and hubs + * are often labeled with these port numbers. The name isn't + * as stable: bus->busnum changes easily from modprobe order, + * cardbus or pci hotplugging, and so on. + */ + if (unlikely(!parent)) { + dev->devpath[0] = '0'; + dev->route = 0; + + dev->dev.parent = bus->controller; + device_set_of_node_from_dev(&dev->dev, bus->sysdev); + dev_set_name(&dev->dev, "usb%d", bus->busnum); + root_hub = 1; + } else { + /* match any labeling on the hubs; it's one-based */ + if (parent->devpath[0] == '0') { + snprintf(dev->devpath, sizeof dev->devpath, + "%d", port1); + /* Root ports are not counted in route string */ + dev->route = 0; + } else { + snprintf(dev->devpath, sizeof dev->devpath, + "%s.%d", parent->devpath, port1); + /* Route string assumes hubs have less than 16 ports */ + if (port1 < 15) + dev->route = parent->route + + (port1 << ((parent->level - 1)*4)); + else + dev->route = parent->route + + (15 << ((parent->level - 1)*4)); + } + + dev->dev.parent = &parent->dev; + dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath); + + if (!parent->parent) { + /* device under root hub's port */ + raw_port = usb_hcd_find_raw_port_number(usb_hcd, + port1); + } + dev->dev.of_node = usb_of_get_device_node(parent, raw_port); + + /* hub driver sets up TT records */ + } + + dev->portnum = port1; + dev->bus = bus; + dev->parent = parent; + INIT_LIST_HEAD(&dev->filelist); + +#ifdef CONFIG_PM + pm_runtime_set_autosuspend_delay(&dev->dev, + usb_autosuspend_delay * 1000); + dev->connect_time = jiffies; + dev->active_duration = -jiffies; +#endif + + dev->authorized = usb_dev_authorized(dev, usb_hcd); + if (!root_hub) + dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0; + + return dev; +} +EXPORT_SYMBOL_GPL(usb_alloc_dev); + +/** + * usb_get_dev - increments the reference count of the usb device structure + * @dev: the device being referenced + * + * Each live reference to a device should be refcounted. + * + * Drivers for USB interfaces should normally record such references in + * their probe() methods, when they bind to an interface, and release + * them by calling usb_put_dev(), in their disconnect() methods. + * However, if a driver does not access the usb_device structure after + * its disconnect() method returns then refcounting is not necessary, + * because the USB core guarantees that a usb_device will not be + * deallocated until after all of its interface drivers have been unbound. + * + * Return: A pointer to the device with the incremented reference counter. + */ +struct usb_device *usb_get_dev(struct usb_device *dev) +{ + if (dev) + get_device(&dev->dev); + return dev; +} +EXPORT_SYMBOL_GPL(usb_get_dev); + +/** + * usb_put_dev - release a use of the usb device structure + * @dev: device that's been disconnected + * + * Must be called when a user of a device is finished with it. When the last + * user of the device calls this function, the memory of the device is freed. + */ +void usb_put_dev(struct usb_device *dev) +{ + if (dev) + put_device(&dev->dev); +} +EXPORT_SYMBOL_GPL(usb_put_dev); + +/** + * usb_get_intf - increments the reference count of the usb interface structure + * @intf: the interface being referenced + * + * Each live reference to a interface must be refcounted. + * + * Drivers for USB interfaces should normally record such references in + * their probe() methods, when they bind to an interface, and release + * them by calling usb_put_intf(), in their disconnect() methods. + * However, if a driver does not access the usb_interface structure after + * its disconnect() method returns then refcounting is not necessary, + * because the USB core guarantees that a usb_interface will not be + * deallocated until after its driver has been unbound. + * + * Return: A pointer to the interface with the incremented reference counter. + */ +struct usb_interface *usb_get_intf(struct usb_interface *intf) +{ + if (intf) + get_device(&intf->dev); + return intf; +} +EXPORT_SYMBOL_GPL(usb_get_intf); + +/** + * usb_put_intf - release a use of the usb interface structure + * @intf: interface that's been decremented + * + * Must be called when a user of an interface is finished with it. When the + * last user of the interface calls this function, the memory of the interface + * is freed. + */ +void usb_put_intf(struct usb_interface *intf) +{ + if (intf) + put_device(&intf->dev); +} +EXPORT_SYMBOL_GPL(usb_put_intf); + +/** + * usb_intf_get_dma_device - acquire a reference on the usb interface's DMA endpoint + * @intf: the usb interface + * + * While a USB device cannot perform DMA operations by itself, many USB + * controllers can. A call to usb_intf_get_dma_device() returns the DMA endpoint + * for the given USB interface, if any. The returned device structure must be + * released with put_device(). + * + * See also usb_get_dma_device(). + * + * Returns: A reference to the usb interface's DMA endpoint; or NULL if none + * exists. + */ +struct device *usb_intf_get_dma_device(struct usb_interface *intf) +{ + struct usb_device *udev = interface_to_usbdev(intf); + struct device *dmadev; + + if (!udev->bus) + return NULL; + + dmadev = get_device(udev->bus->sysdev); + if (!dmadev || !dmadev->dma_mask) { + put_device(dmadev); + return NULL; + } + + return dmadev; +} +EXPORT_SYMBOL_GPL(usb_intf_get_dma_device); + +/* USB device locking + * + * USB devices and interfaces are locked using the semaphore in their + * embedded struct device. The hub driver guarantees that whenever a + * device is connected or disconnected, drivers are called with the + * USB device locked as well as their particular interface. + * + * Complications arise when several devices are to be locked at the same + * time. Only hub-aware drivers that are part of usbcore ever have to + * do this; nobody else needs to worry about it. The rule for locking + * is simple: + * + * When locking both a device and its parent, always lock the + * parent first. + */ + +/** + * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure + * @udev: device that's being locked + * @iface: interface bound to the driver making the request (optional) + * + * Attempts to acquire the device lock, but fails if the device is + * NOTATTACHED or SUSPENDED, or if iface is specified and the interface + * is neither BINDING nor BOUND. Rather than sleeping to wait for the + * lock, the routine polls repeatedly. This is to prevent deadlock with + * disconnect; in some drivers (such as usb-storage) the disconnect() + * or suspend() method will block waiting for a device reset to complete. + * + * Return: A negative error code for failure, otherwise 0. + */ +int usb_lock_device_for_reset(struct usb_device *udev, + const struct usb_interface *iface) +{ + unsigned long jiffies_expire = jiffies + HZ; + + if (udev->state == USB_STATE_NOTATTACHED) + return -ENODEV; + if (udev->state == USB_STATE_SUSPENDED) + return -EHOSTUNREACH; + if (iface && (iface->condition == USB_INTERFACE_UNBINDING || + iface->condition == USB_INTERFACE_UNBOUND)) + return -EINTR; + + while (!usb_trylock_device(udev)) { + + /* If we can't acquire the lock after waiting one second, + * we're probably deadlocked */ + if (time_after(jiffies, jiffies_expire)) + return -EBUSY; + + msleep(15); + if (udev->state == USB_STATE_NOTATTACHED) + return -ENODEV; + if (udev->state == USB_STATE_SUSPENDED) + return -EHOSTUNREACH; + if (iface && (iface->condition == USB_INTERFACE_UNBINDING || + iface->condition == USB_INTERFACE_UNBOUND)) + return -EINTR; + } + return 0; +} +EXPORT_SYMBOL_GPL(usb_lock_device_for_reset); + +/** + * usb_get_current_frame_number - return current bus frame number + * @dev: the device whose bus is being queried + * + * Return: The current frame number for the USB host controller used + * with the given USB device. This can be used when scheduling + * isochronous requests. + * + * Note: Different kinds of host controller have different "scheduling + * horizons". While one type might support scheduling only 32 frames + * into the future, others could support scheduling up to 1024 frames + * into the future. + * + */ +int usb_get_current_frame_number(struct usb_device *dev) +{ + return usb_hcd_get_frame_number(dev); +} +EXPORT_SYMBOL_GPL(usb_get_current_frame_number); + +/*-------------------------------------------------------------------*/ +/* + * __usb_get_extra_descriptor() finds a descriptor of specific type in the + * extra field of the interface and endpoint descriptor structs. + */ + +int __usb_get_extra_descriptor(char *buffer, unsigned size, + unsigned char type, void **ptr, size_t minsize) +{ + struct usb_descriptor_header *header; + + while (size >= sizeof(struct usb_descriptor_header)) { + header = (struct usb_descriptor_header *)buffer; + + if (header->bLength < 2 || header->bLength > size) { + printk(KERN_ERR + "%s: bogus descriptor, type %d length %d\n", + usbcore_name, + header->bDescriptorType, + header->bLength); + return -1; + } + + if (header->bDescriptorType == type && header->bLength >= minsize) { + *ptr = header; + return 0; + } + + buffer += header->bLength; + size -= header->bLength; + } + return -1; +} +EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor); + +/** + * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP + * @dev: device the buffer will be used with + * @size: requested buffer size + * @mem_flags: affect whether allocation may block + * @dma: used to return DMA address of buffer + * + * Return: Either null (indicating no buffer could be allocated), or the + * cpu-space pointer to a buffer that may be used to perform DMA to the + * specified device. Such cpu-space buffers are returned along with the DMA + * address (through the pointer provided). + * + * Note: + * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags + * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU + * hardware during URB completion/resubmit. The implementation varies between + * platforms, depending on details of how DMA will work to this device. + * Using these buffers also eliminates cacheline sharing problems on + * architectures where CPU caches are not DMA-coherent. On systems without + * bus-snooping caches, these buffers are uncached. + * + * When the buffer is no longer used, free it with usb_free_coherent(). + */ +void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags, + dma_addr_t *dma) +{ + if (!dev || !dev->bus) + return NULL; + return hcd_buffer_alloc(dev->bus, size, mem_flags, dma); +} +EXPORT_SYMBOL_GPL(usb_alloc_coherent); + +/** + * usb_free_coherent - free memory allocated with usb_alloc_coherent() + * @dev: device the buffer was used with + * @size: requested buffer size + * @addr: CPU address of buffer + * @dma: DMA address of buffer + * + * This reclaims an I/O buffer, letting it be reused. The memory must have + * been allocated using usb_alloc_coherent(), and the parameters must match + * those provided in that allocation request. + */ +void usb_free_coherent(struct usb_device *dev, size_t size, void *addr, + dma_addr_t dma) +{ + if (!dev || !dev->bus) + return; + if (!addr) + return; + hcd_buffer_free(dev->bus, size, addr, dma); +} +EXPORT_SYMBOL_GPL(usb_free_coherent); + +/* + * Notifications of device and interface registration + */ +static int usb_bus_notify(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct device *dev = data; + + switch (action) { + case BUS_NOTIFY_ADD_DEVICE: + if (dev->type == &usb_device_type) + (void) usb_create_sysfs_dev_files(to_usb_device(dev)); + else if (dev->type == &usb_if_device_type) + usb_create_sysfs_intf_files(to_usb_interface(dev)); + break; + + case BUS_NOTIFY_DEL_DEVICE: + if (dev->type == &usb_device_type) + usb_remove_sysfs_dev_files(to_usb_device(dev)); + else if (dev->type == &usb_if_device_type) + usb_remove_sysfs_intf_files(to_usb_interface(dev)); + break; + } + return 0; +} + +static struct notifier_block usb_bus_nb = { + .notifier_call = usb_bus_notify, +}; + +static void usb_debugfs_init(void) +{ + debugfs_create_file("devices", 0444, usb_debug_root, NULL, + &usbfs_devices_fops); +} + +static void usb_debugfs_cleanup(void) +{ + debugfs_lookup_and_remove("devices", usb_debug_root); +} + +/* + * Init + */ +static int __init usb_init(void) +{ + int retval; + if (usb_disabled()) { + pr_info("%s: USB support disabled\n", usbcore_name); + return 0; + } + usb_init_pool_max(); + + usb_debugfs_init(); + + usb_acpi_register(); + retval = bus_register(&usb_bus_type); + if (retval) + goto bus_register_failed; + retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb); + if (retval) + goto bus_notifier_failed; + retval = usb_major_init(); + if (retval) + goto major_init_failed; + retval = usb_register(&usbfs_driver); + if (retval) + goto driver_register_failed; + retval = usb_devio_init(); + if (retval) + goto usb_devio_init_failed; + retval = usb_hub_init(); + if (retval) + goto hub_init_failed; + retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE); + if (!retval) + goto out; + + usb_hub_cleanup(); +hub_init_failed: + usb_devio_cleanup(); +usb_devio_init_failed: + usb_deregister(&usbfs_driver); +driver_register_failed: + usb_major_cleanup(); +major_init_failed: + bus_unregister_notifier(&usb_bus_type, &usb_bus_nb); +bus_notifier_failed: + bus_unregister(&usb_bus_type); +bus_register_failed: + usb_acpi_unregister(); + usb_debugfs_cleanup(); +out: + return retval; +} + +/* + * Cleanup + */ +static void __exit usb_exit(void) +{ + /* This will matter if shutdown/reboot does exitcalls. */ + if (usb_disabled()) + return; + + usb_release_quirk_list(); + usb_deregister_device_driver(&usb_generic_driver); + usb_major_cleanup(); + usb_deregister(&usbfs_driver); + usb_devio_cleanup(); + usb_hub_cleanup(); + bus_unregister_notifier(&usb_bus_type, &usb_bus_nb); + bus_unregister(&usb_bus_type); + usb_acpi_unregister(); + usb_debugfs_cleanup(); + idr_destroy(&usb_bus_idr); +} + +subsys_initcall(usb_init); +module_exit(usb_exit); +MODULE_LICENSE("GPL"); |